Cleaning C14 Corrector lens

[Eric Watkins]

I’m in the process of cleaning the outer surface of my C14 corrector plate.

There are many references to adding  a few drops of dish washing liquid to distilled water and that some such liquids are unsuitable.

Any advice as to which off the shelf dish washing liquids  are suitable?

Thanks Eric

[Martin Mobberley]

Hello Eric,

I’m not an expert on the relative merits of dish washing liquid I’m afraid!

However, there is some useful advice online (which you may have seen already).

Firstly, the ASO web page:

http://arksky.org/asoclean.htm

Secondly, there’s a very good Starizona video:

https://www.youtube.com/watch?v=loRrpM2MIdk

Also, there’s Ron Arbour’s approach using sellotape, as described in
the 2014 December Journal……only for the brave perhaps?!

Regards,
Martin

[Neil Morrison]

 I would not  advise using any house hold product I have cleaned  the corrector plate of my C8 twice in the last 30 years and used a tiny amount  of Kodak Lens Cleaning  fluid circa 1960.  The C8 is  Vintage 1987 or prior  with no  special coatings .If you go ahead  be sure that when you  replace the plate you install it back  at the very same spot that it was sited  upon before. 

Regards

Neil

[Callum Potter]

I have used Baader Optical Wonder Cleaning Fluid – it seems to do a good job.

Callum

[Richard Miles]

Eric – Distilled water is usually difficult to come by as these days, de-ionised water is often sold (e.g. for lead-acid accumulators). If you can get it then you would only need to use ‘half a drop’ of washing up liquid, i.e. as little as possible, in say a litre of pure water. So say 1 mm cube of detergent would give 1 part in 1 million. Then there’s the problem of getting pure Cotton Wool BP to wipe the surfaces with. You would need the medical sort.

[Eric Watkins]

Thank you for your replies.

Martin. Yes I have seen those short films which have been helpful  I will use the much of the technique described but I’m too afraid to try Ron’s method.

Neil. I’m not removing the corrector plate, just doing the outside and tilting the tube slightly.

Callum.  I have heard the Baader cleaning fluid mentioned to me in the recent past.  I may take a look at that.

Richard, thanks .Yes it’s de-ionised water I have and I will filter it and mix as a solution with isoropyl alcohol .

                       Re the washing up liquid this is usually quoted and advice is not to use the waxy ones.  Would fairy liquid do?

                      I’ll use pure kleenex tissues and get the cotton wool from a pharmacist

Thanks to all for your comments.

  

[Mr Trevor Southam]

Hi Eric

I would be very careful about using washing up liquid as it contains salt, de-ionised water still contains impurities and can leave streaks.

Regards

Trevor

[Gary Poyner]

Washing up liquid also contains lanolin, which can leave white marks if not washed down properly.  I’ve not cleaned a corrector plate (I did have a Meade 14 for 7 years but didn’t clean it and didn’t lose any limiting magnitude either over that time), but have washed more mirrors than you can poke a stick at, and white marks/streaks were certainly a problem if your like me and need everything to be pristine. It was probably this that sent me grey.

If in doubt, leave well alone.

Gary

[Eric Watkins]

Thanks for all comments and suggestions .  I think I will settle for Calum’s suggestion of using Baader Optical Wonder Cleaning Fluid and see how I get on with that having first removed loose dust etc with canned air. 

Regards Eric

[Dominic Ford]

Opticians sell cheap cloths called “microfibre wipes” that are designed to get grease and dirt off pairs of glasses.

I’ve always been really impressed how well they clean my glasses, and have taken to using them on camera lenses too. I’ve never tried them on telescope optics, but I guess they ought to work? I’d be interested to know if anyone else has tried…

[David Arditti]

My method is to use tissues (one per wipe, then use other side, then throw away) plus de-ionised water, plus isopropyl alcohol. I alternate the alcohol washing stage and the water washing stage, going through a few cycles.

The main points I’d emphasise are being gentle, only doing a small arc each time, then lifting the tissue, and not rubbing in circles.

Also, don’t try to get it perfect. They’ll always be streaks. I do it maybe every couple of years, but my location is very dirty, with many diesel vehicles nearby.

[Roger Pickard]

I’ve used Gary’s 14″ Meade for another 7 years and only this year was brave enough to try Ron’s method of Sellotape.  It still left a few marks and checking Ron’s article again he used a standard window cleaner but make sure that it doesn’t contain any vinegar.  Mine didn’t and the plate came up sparkling.  Not sure it really made any difference to the images but at least I’m happier knowing that it must be the sky conditions and not my telescope if things are not as good as I feel they should be.

Cheers,

Roger

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